U.S. Pat. No. 3,817,911 describes the production of "composite" materials that are mixtures of organic and inorganic polymers. The mixtures are made by the simultaneous formation of the organic and inorganic polymers. In all of the Examples in this patent it is reported that the organic polymer may be extracted (dissolved) by organic solvent.
H. Schmidt, J. Non-Cryst. Sol., vol. 73, p. 681-691 (1985) presents a general discussion of mixtures of inorganic and organic polymers, especially mixtures in which the inorganic and organic polymers are bound together through ionic, coordination or covalent bonds. Although some uses such as scratch resistant coatings are referred to, relatively little information is provided regarding methods for preparation of the mixtures and their resulting properties.
European Patent Application Publication No. 281,082 describes general methods of making mixtures of inorganic oxides or other aluminum salts with organic polymers. The methods described, both in the Specification and Examples are general, and no specific properties of the resulting mixtures are given.
U.S. Pat. No. 4,772,660 describes the preparation of mixtures of a polymerizable monomer, such as an acrylic type monomer, with a silica or alumina sol. The polymerizable monomer is polymerized by irradiation to form the inorganic-organic polymer mixture. The properties of the final polymer mixture are not described.
E. J. A. Pope, et al., J. Mater. Res., vol. 4, p. 1018-1026 (1989) describe the preparation of transparent silica gel-poly(methyl methacrylate) composites (mixtures). These are made by impregnating silica gel with methyl methacrylate and polymerizing the methyl methacrylate. The resulting mixture is reported to have a measurable glass transition temperature.
H. Schmidt, J. Non-Cryst. Sol., vol. 112, p. 419-423 (1989) describes mixtures of inorganic oxides with organic polymers, which are reported to be single phase. In the examples disclosed, the presence of functional monomers allows the inorganic and organic polymers to bond covalently to each other.
T. Saegusa and Y. Chujo, Abstracts of the 33rd IUPAC International Symposium on Macromolecules, Montreal Canada, Jul. 8-13, 1990, report a series of "homogeneous transparent solid materials" which are mixtures of silica gel and organic polymers having repeating N,N-dialkyl carboxylic amide groups. The authors report that the organic polymer is either extractable with solvent or is covalently bound to the inorganic polymer (silica).
M. W. Ellsworth and B. M. Novak, J. Am. Chem. Soc., vol. 113, p. 2756-2758 disclose the preparation of mixtures of certain olefinic polymers and silica by the simultaneous polymerization of the olefin and the formation of silica by hydrolysis of a silica precursor. In some cases the organic polymer is reported to be nonextractable by solvents. However, in these cases, the possibility of covalent bonding between the organic polymer and silica exists. This question is not addressed by the authors.
C. J. Wung, et al., Polymer, vol. 32, No. 4 , p 605-608 (1991) describe the preparation of a poly(p-phenylene vinylene)-silica composite that exhibits third order nonlinear optical properties. This composite is made by heating a mixture of the silica and a polymer which is a precursor to the poly(p-phenylene vinylene).